as flour improvers; their active fat-oxidizing
enzymes, which generate the typical beany
flavor, also indirectly cause the oxidation and
elongation of gluten proteins.
The traditional air-aging of flour had a
visible side effect: the yellowish flour
becomes progressively paler as the
xanthophyll pigments are oxidized to a
colorless form. Once the chemistry of this
change was understood, millers began using
bleaching agents (azodicarbonamide,
peroxide) to whiten flours. Many bakers
prefer to use unbleached flours because they
have been subjected to less chemical
alteration. Bleaching is not allowed in Europe.
Minor Flour Components
The gluten proteins and starch granules in
flour account for about 90% of flour weight,
and for much of the behavior of flour doughs
and batters. But some minor components have